Electrical apparatus.



W. S. HAUAWAKI@ E. E. ROSE. ELECTRICAL APPARATUS,

APPLICATION msn xuLY 2.1913.

1,1 58,488. patented Nov. 2, 1915.

ATTURNEY nel 'and useful Improvement in Electricl pai-attrs, of which the following is a speciiii UNITED srarask Piirnivr OFFICE.

WILLIAM S. HADAWAY, JR., OF NEV ROCHELLE, vNEW YORK', AND EDWARD E. Ross,

OF SVJISSVALE, PENNSYLVANIA, ASSIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A. CORPORATION OF PENNSYLVANIA.-

ELECTRICAL APPARATUS.

To all whom t may concern.'

Be it known that we, VILLIAM SjHADA- WAY, Jr., and EDWARD E. ROSE, citizens of the United States, and residents, respec-v tively, of New Rochelle, in the' county of W estchester and State of N ew York, and Swissvale, in the county of Allegheny and State of Pennsylvania, have invented a nsw cation, this being a division of application, Serial No. 543,399, iilcd February 11, 1910.

Ourr invention relates to electrical apparatus and it has special immersion in a liquid.

One object of our invention is to provide an apparatus of the abovefindicated character which shall be compact and durable in construction and efficient in operation.'

Another object of our invention is to pro` vide an electric heater 'unit which shall embody Afeatmes that particularly adapt it for operation at a relatively high output per unit of weight and volume Without deterioration of the parts.

In our cti-pending application, Serial No. 543,399,'liled February 11, 1910, of which .this application is a division., We have shojwn. and described the preferred embodhnentof our heater'units and have set forth their operation in a system ot' boiler heating?. Hereinafter, therefore, we shall set forth onlythe construction of vthe heater unit itself, and it should` be understood that many modifications in structural details may be made within the spirit and scope of our invention.

According to our invention, we provide an electric heater that embodies a. conduc` tor, a flexible dielectric cell therefor, and. suitable heat-resisting insulating material disposed intermediate the conductor and the cell. v

""Inthe-accompanying drawing, nigu're 1 1s i a view, in section, of a liquid-containing' vessel embodying an apparatus shown in elevation and constructed in accordance with our invention; 2 and 3 are sectional. views, on the linesl1-ll and Illa-Ill, respectively, of Fig. et; Fig. 4 is an enlarged plan view, with paits broken away for clearness, of a heater unit shown in Fig. 1; and

Specification 01"' Letters Patent.

t reference to electricheatingl elements of the type adapted for Patenten Noir. 2, 1915.

`Referring; to the drawing, a heater unit l 1s suitably embodied in a liquid-contaimng vessel 1a and comprises a conducting' member 2, insulatingl .'iaterial 3 disposed adjacent thereto, a supporting cell 3, an insulating cell` 4, and a. suitable inclosing protective member 5.

The conducting' member or resistance unit 2 comprises a strip or ribbon, the ends of which may constitute suitable terminals for the heater unit 1 and the ii'itern'iediate portion of which may or may not be provided with a series of slots cut 'alternately in the opposite edges to provide a zig-Zag path for electricA current.

Ordinary insulatingr fabrics are unsuitable for embodiment in our heater unit since, in general, they are composed of materials, or contain materials, which become carbonized -when subjected to high temperatures. lf such materials are employed, after a short time they become incapable of withstanding high voltages since they are partially conduct-ingr when carbo'nizcd, and we accordingly provide thesl'iecial combination of -insulating' materials 3, 3a and 4, which per# mits a.v high temperature and, consequently, a high heat output. andwhich is preferably produced asV follows: A molded cell et is first formed by building upA white mica splittints, in the usual manner, a. minimum amount of insulating varnish o .n other bonding material being' employed. As shown in Fig: 5, the cell is molded into the form of achanilelbar or strip having very thin Walls. Relatively large lwhite mica splitting's 3 are next spread over the inner surface of the celhjvith their edges over lapping', until a mica lining of the desired thickness is produced. Two layers of clear white mica strips y3, which are cut to the exact width of the cell and are of uniform lengths, are next carefully placed Within the layers of mica already provided, in such manner that the strips in each layer are end to end and the spaces between the strips in one laver do not come opposite the spaces in the other layer.

The resistance ribbon 2 is provided with 'and this application filedJuly 2,

material.

vided with a slot through which the ribbon is threaded, and then the ribbon is placed in position in the cell 3a. The strips through Which the ribbon is threaded correspond in Width to the cell and are spaced apart in such manner as to keep the ribbon in the center of the cell throughout its entire length. Still more mica is next laid 'over the ribbonl and finally, the cell 4 is heated and is bent over to envelop the ribbon andv is allowed to cool While it is held inthis position, under pressure.

The cell 3a, which is molded as above indicated, is intended to hold the clear mica strips 3 in positionv and it may be `replaced by a thin sheet metal cell or other suitable `structure of either insulating or ,conductingI Outside of this cell the Wrapping or outer cell 4 of flexible molded mica insulation yis provided for the purpose'of electrically separating the resistance element from the flattened metal tube or armor 5 with which the insulation is protected and separated from the Huid in the vessel.

The outer insulating cell 4 has a very high dielectric strength and is sutiicient in itself to prevent the grounding of the resistance elenent Within. At the same time, the tem perature to which it may be subjected without abnormal deterioration is limited, and, for this reason, the clear mica is interposed between the resistance element, which is very het, and the outer insulating cell, which, as

hereinafter pointed out, is in close contact.

rufith the metal sheath or containing tube 5 which, in turn, is in contact with the fluid in the vessel and, consequently, is maintained vatf a much lower temperature than the resistance element.

After-the resistance ribbon is insulated, as above indicated, it is threaded through a flattened Ietal tube 5 which 'is afterward further flattened .under high pressure in order that the heat generated in the resistance ribbofn may be readily conducted to the fluid in th' vessel.

Each of the metallsheaths in which the reare disposed may consist-v sistance elements metal welded" together 'at of two strips of their edges instead of the flattened tube above described.

.'We claim as our 1nvent1on: 1. A resistance unlt comprislng a conducting member, a flexible dielectric cell, and

interposed heat-resisting insulation.

2. A resistance unit comprising-a conducting member, a flexible dielectric cell, and ini ter'posed clear mica insulation.

3. A resistance unit comprismga conducting member, an outer cell or Wrapping of high dielectric strength and interposed overlapping sheets or flakes of clear mica.

4. A resistance unit comprising a currentconducting member, a covering therefor of heat-resisting insulation, means for holding the said'covering in position, andan outeI` cell or wrapping of insulating material having a high dielectric strength. l

5. A resistance unit comprising a'currentconducting member, a clear mica covering therefor, means for holdingthe clear mica in position, an outer cell or Wrapping 44of flexible insulating material of high dielecf tric strength and a metal casing or armor which is pressed into close engagement with the inclosed parts.

6. A resistance unit comprising a conducting member, a dielectric enveloping cell surrounding the said conducting member, and interposed heat-resisting insulation.

In testimony whereof, I have hereunto subscribed -my name this 14th day of June, i

l. vWILLIAM S. HADAWAY, JR. Witnesses:

Gr. vP. BROCKWAY, Y ARTHUAR N nHLs,

InY testimony whereof, l have hereunto subscribed my name this 27th day of June, 1913.

Nitnessesz B. B. HINES, M.l C. Manz.

EDWARD n. Rose. 

